Laravel eloquent query result always empty

I've been spinning my wheels on this for hours. Here's the deal. This works fine:

$logs = ViewLog::where('created_at', '>=', $start)
               ->where('created_at', '<=', $end)
               ->get();

And this also works fine:

$logs = ViewLog::where('item_id', $id)->get();

But, even though there are records that match this query, it returns an empty collection:

$logs = ViewLog::where('created_at', '>=', $start)
               ->where('created_at', '<=', $end)
               ->where('item_id', $id)
               ->get();

What's more infuriating is that the exact query that always comes back empty in my code, works flawlessly when using tinker. Has anyone ever run into a similar issue?

Updated to answer Maantje's question in the comments

Output of dd(DB::getQueryLog()); :

array:1 [▼
  0 => array:3 [▼
    "query" => "select * from `view_logs` where `created_at` >= ? and `created_at` <= ? and `object3d_id` = ?"
    "bindings" => array:3 [▼
      0 => "2016-05-01 00:00:00"
      1 => "2016-05-31 23:59:59"
      2 => 24
    ]
    "time" => 0.77
  ]
]

via Chebli Mohamed